Airline shares staged a strong comeback on three continents on Monday after European governments bridged a gap in war risk insurance and U.S. carriers were close to getting cash they desperately needed for their immediate survival. 

But analysts cautioned that despite the share rally, the outlook for the global sector remains cloudy. No one yet is able to predict with any certainty how long the U.S. hijacked plane attacks on Sept. 11 and possible retaliatory action by Washington would hurt airlines' long-term ticket sales, they say. 

In the United States, airline experts said the $15 billion bailout signed by President Bush on Saturday shifted the focus for survival to carriers that have the strongest fundamentals and less on how much money they have at this moment. 

``The battle of the hubs is on,'' said Salomon Smith Barney airline analyst Brian Harris. ``There are going to be some keepers that are going to make it through this.'' 

Load Factors Up 

In an important signal, spokesmen for both Northwest Airlines and UAL Corp.'s United Airlines said load factors, or percentage of seats filled, were back around the 50 percent level. That means planes are still only half full, but better than last week, when one major airline said planes were only slightly more than one-third full. 

David Swierenga, chief economist for the Air Transport Association, told Reuters that carriers were still bringing in revenues that were only 50 percent of what they were before the attacks. He said airlines were submitting data to authorities by noon EDT and may have wire transfers of up to half the available cash by today. 

``The airlines are really desperate to get this because there were several carriers teetering on the edge of bankruptcy,'' Swierenga said. 

Employee cutbacks, totaling more than 100,000 in the United States, were also continuing. Delta Air Lines, the only one of the majors which has not yet announced layoffs, said a decision on reductions at the No. 3 carrier would be coming soon. 

European Carriers on the Edge 

``It is all still very uncertain,'' said Deutsche Bank analyst Jonathan Wober, noting that even small changes in revenue would have huge effects on the profitability of an industry already operating with low margins and high debt. 

The survival of some U.S. airlines has been in doubt since the day of the attacks, but on Monday analysts wondered whether the damage would also push some already troubled European carriers over the edge, perhaps even ``national'' airlines whose existence has always been politically sacrosanct. 

One of those, Swissair Group, said on Monday it was in a fight for survival and urgently needed 2 billion to 3 billion Swiss francs ($1.3 billion to $1.8 billion) in new equity as well as radical cutbacks in its operations. 

And unions and management at another ailing national carrier, Belgium's disastrously unprofitable Sabena, in which Swissair is a 49.5 percent shareholder, were expected to resume talks on a restructuring plan. 

But share prices for the three largest European airlines -- British Airways Plc, Deutsche Lufthansa AG and Air France SA -- were all up, with BA up more than 10 percent at 167-1/2 pence by 1430 GMT, Lufthansa up 5.3 percent at 9.35 euros and Air France 13 percent higher at 10.15 euros. 

Prices also advanced for major Asian carriers, including Singapore Airlines Ltd, Qantas Airways Ltd in Australia and Hong Kong's Cathay Pacific Airways Ltd. 

On the New York Stock Exchange, shares of US Airways Group rose 13 percent to $5.16, shares of Continental Airlines rose 11 percent to $16.26 and those of America West were up 13 percent to $2.82. The top three carriers -- AMR Corp, United and Delta -- were up 5 to 9 percent. 

War Insurance 

Until governments stepped in over the past few days, airlines had faced the risk of being grounded for want of adequate insurance. Insurers had massively hiked premiums for certain types of coverage and reduced their potential exposure for third party war risks. 

The solution has been state insurance or state payments to offset the cost of liability coverage. 

In the United States help for airlines is set to be extensive, with the $5 billion cash and $10 billion in loan guarantees, as well as government-backed insurance against war and terrorism risk for the next six months. 

The extent of damage to each airline's operations varies greatly, but appears to depend a lot on how much of its revenue is generated on U.S. flights. 

British Airways, Europe's biggest airline and one of the most dependent on transatlantic services, said it was considering options for raising cash, including the sale of property, if losses from the attacks in the United States grew. 

Swissair, on its knees even before the attacks because of an unsuccessful expansion strategy, said the latest developments had forced it to lay off 3,000 people initially from its catering unit and to slash its long-haul aircraft fleet by a quarter. 

``Everybody has to make a sacrifice, otherwise this company will not survive,'' Chairman Mario Corti told Swiss radio. 

Bankruptcies Still Very Possible 

The possibility of airlines not surviving is exactly what analysts are contemplating. 

``There are bound to be a small number of airlines that are at risk of going bust,'' said Mike Powell from Dresdner Kleinwort Wasserstein in London. 

Almost two weeks after the attacks, only sketchy evidence is available on how badly airlines have been hit and almost none at all on how many frightened passengers have been deterred from flying in the longer term -- say, over the next year or so. 

Powell estimated that European carriers' traffic would not recover for eight months, and even then it would only reach its level of immediately before the attacks -- still less than what it should have been by that time. 

The attacks are expected to add to the cost of air travel because of extra security measures, further deterring passengers, and KLM Royal Dutch Airlines said on Monday it had begun charging a surcharge of $10 for each return flight. 

``It's a safety surcharge,'' a spokesman said. ``We have taken a lot of measures to boost safety, and that incurs costs.'' 

The attacks have also hurt the value of aviation asset sales. The Australian government on Monday deferred the sale of Sydney airport until early 2002, saying the turmoil threatened to cut the A$4.5 billion ($2.2 billion) price tag. The sale of Kingsford Smith airport had been due to be completed by the end of the year.

Reuters contributed to this report.